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<div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*</span>
<a name="l00002"></a>00002 <span class="comment"> * Copyright (c) 2010-2011, NVIDIA Corporation</span>
<a name="l00003"></a>00003 <span class="comment"> * All rights reserved.</span>
<a name="l00004"></a>00004 <span class="comment"> *</span>
<a name="l00005"></a>00005 <span class="comment"> * Redistribution and use in source and binary forms, with or without</span>
<a name="l00006"></a>00006 <span class="comment"> * modification, are permitted provided that the following conditions are met:</span>
<a name="l00007"></a>00007 <span class="comment"> *   * Redistributions of source code must retain the above copyright</span>
<a name="l00008"></a>00008 <span class="comment"> *     notice, this list of conditions and the following disclaimer.</span>
<a name="l00009"></a>00009 <span class="comment"> *   * Redistributions in binary form must reproduce the above copyright</span>
<a name="l00010"></a>00010 <span class="comment"> *     notice, this list of conditions and the following disclaimer in the</span>
<a name="l00011"></a>00011 <span class="comment"> *     documentation and/or other materials provided with the distribution.</span>
<a name="l00012"></a>00012 <span class="comment"> *   * Neither the name of NVIDIA Corporation nor the</span>
<a name="l00013"></a>00013 <span class="comment"> *     names of its contributors may be used to endorse or promote products</span>
<a name="l00014"></a>00014 <span class="comment"> *     derived from this software without specific prior written permission.</span>
<a name="l00015"></a>00015 <span class="comment"> *</span>
<a name="l00016"></a>00016 <span class="comment"> * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS &quot;AS IS&quot; AND</span>
<a name="l00017"></a>00017 <span class="comment"> * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED</span>
<a name="l00018"></a>00018 <span class="comment"> * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE</span>
<a name="l00019"></a>00019 <span class="comment"> * DISCLAIMED. IN NO EVENT SHALL &lt;COPYRIGHT HOLDER&gt; BE LIABLE FOR ANY</span>
<a name="l00020"></a>00020 <span class="comment"> * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES</span>
<a name="l00021"></a>00021 <span class="comment"> * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;</span>
<a name="l00022"></a>00022 <span class="comment"> * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND</span>
<a name="l00023"></a>00023 <span class="comment"> * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT</span>
<a name="l00024"></a>00024 <span class="comment"> * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS</span>
<a name="l00025"></a>00025 <span class="comment"> * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.</span>
<a name="l00026"></a>00026 <span class="comment"> */</span>
<a name="l00027"></a>00027 
<a name="l00028"></a>00028 <span class="keyword">namespace </span>nih {
<a name="l00029"></a>00029 
<a name="l00030"></a>00030 <span class="comment">//</span>
<a name="l00031"></a>00031 <span class="comment">// IndexSortPredicate implementation.</span>
<a name="l00032"></a>00032 <span class="comment">//</span>
<a name="l00033"></a>00033 
<a name="l00034"></a>00034 <span class="comment">// Predicate to sort indices based on their entity&#39;s AABB center.</span>
<a name="l00035"></a><a class="code" href="classnih_1_1_bvh__sah__builder_1_1_index_sort_predicate.html">00035</a> <span class="keyword">class </span><a class="code" href="classnih_1_1_bvh__sah__builder_1_1_index_sort_predicate.html">Bvh_sah_builder::IndexSortPredicate</a>
<a name="l00036"></a>00036 {
<a name="l00037"></a>00037 <span class="keyword">public</span>:
<a name="l00038"></a>00038     <a class="code" href="classnih_1_1_bvh__sah__builder_1_1_index_sort_predicate.html">IndexSortPredicate</a>(<span class="keyword">const</span> std::vector&lt;Entity&gt;&amp; entities, <span class="keywordtype">int</span> dim)
<a name="l00039"></a>00039       : m_entities( entities ),
<a name="l00040"></a>00040         m_dim( dim )
<a name="l00041"></a>00041     {}
<a name="l00042"></a>00042 
<a name="l00043"></a>00043     <span class="keywordtype">bool</span> operator() (<span class="keywordtype">int</span> lhs, <span class="keywordtype">int</span> rhs)<span class="keyword"> const</span>
<a name="l00044"></a>00044 <span class="keyword">    </span>{
<a name="l00045"></a>00045         <span class="keyword">const</span> <a class="code" href="structnih_1_1_bbox.html">Bbox3f</a>&amp; left  = m_entities[lhs].m_bbox;
<a name="l00046"></a>00046         <span class="keyword">const</span> <a class="code" href="structnih_1_1_bbox.html">Bbox3f</a>&amp; right = m_entities[rhs].m_bbox;
<a name="l00047"></a>00047         <span class="keyword">const</span> <span class="keywordtype">float</span> leftval  =  left.<a class="code" href="structnih_1_1_bbox.html#a1d8ccda901cd9ecfe7ad40d046362936" title="min corner">m_min</a>[m_dim]  + left.<a class="code" href="structnih_1_1_bbox.html#acf51fbadf69955a4a12641d96b17a9b8" title="max corner">m_max</a>[m_dim];
<a name="l00048"></a>00048         <span class="keyword">const</span> <span class="keywordtype">float</span> rightval = right.<a class="code" href="structnih_1_1_bbox.html#a1d8ccda901cd9ecfe7ad40d046362936" title="min corner">m_min</a>[m_dim] + right.<a class="code" href="structnih_1_1_bbox.html#acf51fbadf69955a4a12641d96b17a9b8" title="max corner">m_max</a>[m_dim];
<a name="l00049"></a>00049         <span class="keywordflow">return</span> leftval &lt; rightval;
<a name="l00050"></a>00050     }
<a name="l00051"></a>00051 
<a name="l00052"></a>00052 <span class="keyword">private</span>:
<a name="l00053"></a>00053     <span class="keyword">const</span> std::vector&lt;Entity&gt;&amp;  m_entities;
<a name="l00054"></a>00054     <span class="keywordtype">int</span>                         m_dim;
<a name="l00055"></a>00055 };
<a name="l00056"></a>00056 
<a name="l00057"></a>00057 <span class="keyword">inline</span> <span class="keywordtype">void</span> <a class="code" href="classnih_1_1_bvh__sah__builder.html#aa056c2970c0dcf4f155f90f7a56355eb">Bvh_sah_builder::build</a>(
<a name="l00058"></a>00058     <span class="keyword">const</span> uint32    n_entities,
<a name="l00059"></a>00059     <a class="code" href="structnih_1_1_bvh.html">Bvh_type</a>*       bvh,
<a name="l00060"></a>00060     <a class="code" href="structnih_1_1_bvh__sah__builder_1_1_stats.html">Stats</a>*          stats)
<a name="l00061"></a>00061 {
<a name="l00062"></a>00062    std::vector&lt;Bvh_node_type&gt;&amp; nodes = bvh-&gt;m_nodes;
<a name="l00063"></a>00063 
<a name="l00064"></a>00064     <span class="comment">// initialize tag bits</span>
<a name="l00065"></a>00065     m_tag_bits.resize( n_entities, <span class="keyword">false</span> );
<a name="l00066"></a>00066 
<a name="l00067"></a>00067     <span class="comment">// Initialize indices.</span>
<a name="l00068"></a>00068     m_tmpInt.resize( n_entities );
<a name="l00069"></a>00069 
<a name="l00070"></a>00070     m_indices[0].resize( n_entities );
<a name="l00071"></a>00071     <span class="keywordflow">for</span>(uint32 i = 0; i &lt; n_entities; ++i)
<a name="l00072"></a>00072         m_indices[0][i] = static_cast&lt;int&gt;( i );
<a name="l00073"></a>00073 
<a name="l00074"></a>00074     <span class="keywordflow">for</span>(<span class="keywordtype">int</span> dim = 1; dim &lt; 3; ++dim)
<a name="l00075"></a>00075         m_indices[dim] = m_indices[0];
<a name="l00076"></a>00076 
<a name="l00077"></a>00077     <span class="comment">// Sort index arrays by their dimension.</span>
<a name="l00078"></a>00078     <a class="code" href="classnih_1_1_bvh__sah__builder_1_1_index_sort_predicate.html">IndexSortPredicate</a> pred_x( m_entities, 0 );
<a name="l00079"></a>00079     <a class="code" href="classnih_1_1_bvh__sah__builder_1_1_index_sort_predicate.html">IndexSortPredicate</a> pred_y( m_entities, 1 );
<a name="l00080"></a>00080     <a class="code" href="classnih_1_1_bvh__sah__builder_1_1_index_sort_predicate.html">IndexSortPredicate</a> pred_z( m_entities, 2 );
<a name="l00081"></a>00081     std::sort( m_indices[0].begin(), m_indices[0].end(), pred_x );
<a name="l00082"></a>00082     std::sort( m_indices[1].begin(), m_indices[1].end(), pred_y );
<a name="l00083"></a>00083     std::sort( m_indices[2].begin(), m_indices[2].end(), pred_z );
<a name="l00084"></a>00084 
<a name="l00085"></a>00085     <span class="comment">// create root</span>
<a name="l00086"></a>00086     <a class="code" href="structnih_1_1_bbox.html">Bbox3f</a> root_bbox;
<a name="l00087"></a>00087     compute_bbox( 0u, n_entities, root_bbox );
<a name="l00088"></a>00088 
<a name="l00089"></a>00089     Node_stack node_stack;
<a name="l00090"></a>00090     {
<a name="l00091"></a>00091         Node node;
<a name="l00092"></a>00092         node.m_bbox  = root_bbox;
<a name="l00093"></a>00093         node.m_begin = 0u;
<a name="l00094"></a>00094         node.m_end   = n_entities;
<a name="l00095"></a>00095         node.m_depth = 0u;
<a name="l00096"></a>00096         node.m_node  = 0u;
<a name="l00097"></a>00097 
<a name="l00098"></a>00098         node_stack.push( node );
<a name="l00099"></a>00099     }
<a name="l00100"></a>00100 
<a name="l00101"></a>00101     <span class="keywordflow">if</span> (stats)
<a name="l00102"></a>00102         stats-&gt;m_max_depth = 0u;
<a name="l00103"></a>00103 
<a name="l00104"></a>00104     Bvh_node_type root = Bvh_node_type( Bvh_node::kInternal, 0u, uint32(-1) );
<a name="l00105"></a>00105     nodes.erase( nodes.begin(), nodes.end() );
<a name="l00106"></a>00106     nodes.push_back( root );
<a name="l00107"></a>00107     bvh-&gt;m_bboxes.resize( 1u );
<a name="l00108"></a>00108     bvh-&gt;m_bboxes[0] = root_bbox;
<a name="l00109"></a>00109 
<a name="l00110"></a>00110     <span class="keywordflow">while</span> (node_stack.empty() == <span class="keyword">false</span>)
<a name="l00111"></a>00111     {
<a name="l00112"></a>00112         <span class="keyword">const</span> Node node = node_stack.top();
<a name="l00113"></a>00113         node_stack.pop();
<a name="l00114"></a>00114 
<a name="l00115"></a>00115         <span class="keyword">const</span> uint32 node_index = node.m_node;
<a name="l00116"></a>00116         <span class="keyword">const</span> Bbox_type bbox    = node.m_bbox;
<a name="l00117"></a>00117 
<a name="l00118"></a>00118         <span class="comment">// set the node bbox</span>
<a name="l00119"></a>00119         bvh-&gt;m_bboxes[ node_index ] = bbox;
<a name="l00120"></a>00120 
<a name="l00121"></a>00121         <span class="keywordflow">if</span> (stats)
<a name="l00122"></a>00122             stats-&gt;m_max_depth = <a class="code" href="group__vectors.html#gab2b34b1991185fc29890973777b60e54">std::max</a>( stats-&gt;m_max_depth, node.m_depth );
<a name="l00123"></a>00123 
<a name="l00124"></a>00124         <span class="keywordflow">if</span> (node.m_end - node.m_begin &lt;= m_max_leaf_size)
<a name="l00125"></a>00125         {
<a name="l00126"></a>00126             <span class="comment">//</span>
<a name="l00127"></a>00127             <span class="comment">// Make a leaf node</span>
<a name="l00128"></a>00128             <span class="comment">//</span>
<a name="l00129"></a>00129             Bvh_node_type&amp; bvh_node = nodes[ node_index ];
<a name="l00130"></a>00130             <span class="keywordflow">if</span> (m_partial_build)
<a name="l00131"></a>00131                 bvh_node = Bvh_node_type( Bvh_node::kLeaf, node.m_begin, node.m_end );
<a name="l00132"></a>00132             <span class="keywordflow">else</span>
<a name="l00133"></a>00133             {
<a name="l00134"></a>00134                 bvh_node = Bvh_node_type( Bvh_node::kLeaf, uint32( bvh-&gt;m_leaves.size() ), uint32(-1) );
<a name="l00135"></a>00135 
<a name="l00136"></a>00136                 bvh-&gt;m_leaves.push_back( <a class="code" href="structnih_1_1_bvh__leaf.html">Bvh_leaf</a>( node.m_end - node.m_begin, node.m_begin ) );
<a name="l00137"></a>00137             }
<a name="l00138"></a>00138         }
<a name="l00139"></a>00139         <span class="keywordflow">else</span>
<a name="l00140"></a>00140         {
<a name="l00141"></a>00141             <span class="comment">//</span>
<a name="l00142"></a>00142             <span class="comment">// Make a split node</span>
<a name="l00143"></a>00143             <span class="comment">//</span>
<a name="l00144"></a>00144 
<a name="l00145"></a>00145             uint32    middle;
<a name="l00146"></a>00146             Bbox_type l_bb, r_bb;
<a name="l00147"></a>00147 
<a name="l00148"></a>00148             <span class="keywordflow">if</span> (find_best_split( node, middle, l_bb, r_bb ) == <span class="keyword">false</span>)
<a name="l00149"></a>00149             {
<a name="l00150"></a>00150                 <span class="keywordflow">if</span> (m_force_splitting)
<a name="l00151"></a>00151                 {
<a name="l00152"></a>00152                     middle = (node.m_begin + node.m_end) / 2;
<a name="l00153"></a>00153                     compute_bbox( node.m_begin, middle, l_bb );
<a name="l00154"></a>00154                     compute_bbox( middle, node.m_end, r_bb );
<a name="l00155"></a>00155                 }
<a name="l00156"></a>00156                 <span class="keywordflow">else</span>
<a name="l00157"></a>00157                 {
<a name="l00158"></a>00158                     <span class="comment">// unsuccessful split: make a leaf node</span>
<a name="l00159"></a>00159                     Bvh_node_type&amp; bvh_node = nodes[ node_index ];
<a name="l00160"></a>00160                     <span class="keywordflow">if</span> (m_partial_build)
<a name="l00161"></a>00161                         bvh_node = Bvh_node_type( Bvh_node::kLeaf, node.m_begin, node.m_end );
<a name="l00162"></a>00162                     <span class="keywordflow">else</span>
<a name="l00163"></a>00163                     {
<a name="l00164"></a>00164                         bvh_node = Bvh_node_type( Bvh_node::kLeaf, uint32( bvh-&gt;m_leaves.size() ), uint32(-1) );
<a name="l00165"></a>00165 
<a name="l00166"></a>00166                         bvh-&gt;m_leaves.push_back( Bvh_leaf( node.m_end - node.m_begin, node.m_begin ) );
<a name="l00167"></a>00167                     }
<a name="l00168"></a>00168                     <span class="keywordflow">continue</span>;
<a name="l00169"></a>00169                 }
<a name="l00170"></a>00170             }
<a name="l00171"></a>00171 
<a name="l00172"></a>00172             <span class="comment">// alloc space for children</span>
<a name="l00173"></a>00173             <span class="keyword">const</span> uint32 left_node_index = uint32( nodes.size() );
<a name="l00174"></a>00174             nodes.resize( left_node_index + 2 );
<a name="l00175"></a>00175             bvh-&gt;m_bboxes.resize( left_node_index + 2 );
<a name="l00176"></a>00176 
<a name="l00177"></a>00177             Bvh_node_type&amp; bvh_node = nodes[ node_index ];
<a name="l00178"></a>00178             bvh_node = Bvh_node_type( Bvh_node_type::kInternal, left_node_index, uint32(-1) );
<a name="l00179"></a>00179 
<a name="l00180"></a>00180             <span class="comment">// push left and right children in processing queue</span>
<a name="l00181"></a>00181             Node right_node;
<a name="l00182"></a>00182             right_node.m_bbox  = r_bb;
<a name="l00183"></a>00183             right_node.m_begin = middle;
<a name="l00184"></a>00184             right_node.m_end   = node.m_end;
<a name="l00185"></a>00185             right_node.m_depth = node.m_depth + 1u;
<a name="l00186"></a>00186             right_node.m_node  = left_node_index + 1u;
<a name="l00187"></a>00187             node_stack.push( right_node );
<a name="l00188"></a>00188 
<a name="l00189"></a>00189             Node left_node;
<a name="l00190"></a>00190             left_node.m_bbox  = l_bb;
<a name="l00191"></a>00191             left_node.m_begin = node.m_begin;
<a name="l00192"></a>00192             left_node.m_end   = middle;
<a name="l00193"></a>00193             left_node.m_depth = node.m_depth + 1u;
<a name="l00194"></a>00194             left_node.m_node  = left_node_index;
<a name="l00195"></a>00195             node_stack.push( left_node );
<a name="l00196"></a>00196         }
<a name="l00197"></a>00197     }
<a name="l00198"></a>00198 
<a name="l00199"></a>00199     <span class="keywordflow">if</span> (m_partial_build == <span class="keyword">false</span>)
<a name="l00200"></a>00200         build_skip_nodes( &amp;bvh-&gt;m_nodes[0], &amp;bvh-&gt;m_nodes[0], uint32(-1) );
<a name="l00201"></a>00201 }
<a name="l00202"></a>00202 
<a name="l00203"></a>00203 <span class="keyword">template</span> &lt;<span class="keyword">typename</span> Iterator&gt;
<a name="l00204"></a><a class="code" href="classnih_1_1_bvh__sah__builder.html#aa056c2970c0dcf4f155f90f7a56355eb">00204</a> <span class="keywordtype">void</span> <a class="code" href="classnih_1_1_bvh__sah__builder.html#aa056c2970c0dcf4f155f90f7a56355eb">Bvh_sah_builder::build</a>(
<a name="l00205"></a>00205     <span class="keyword">const</span> Iterator  begin,
<a name="l00206"></a>00206     <span class="keyword">const</span> Iterator  end,
<a name="l00207"></a>00207     <a class="code" href="structnih_1_1_bvh.html">Bvh_type</a>*       bvh,
<a name="l00208"></a>00208     <a class="code" href="structnih_1_1_bvh__sah__builder_1_1_stats.html">Stats</a>*          stats)
<a name="l00209"></a>00209 {
<a name="l00210"></a>00210     <span class="keyword">const</span> uint32 n_entities = uint32( end - begin );
<a name="l00211"></a>00211 
<a name="l00212"></a>00212     m_entities.resize( n_entities );
<a name="l00213"></a>00213     uint32 i = 0;
<a name="l00214"></a>00214     <span class="keywordflow">for</span> (Iterator it = begin; it != end; ++it)
<a name="l00215"></a>00215     {
<a name="l00216"></a>00216         m_entities[i].m_bbox  = *it;
<a name="l00217"></a>00217         m_entities[i].m_index = i;
<a name="l00218"></a>00218         m_entities[i].m_cost  = 1.0f;
<a name="l00219"></a>00219 
<a name="l00220"></a>00220         i++;
<a name="l00221"></a>00221     }
<a name="l00222"></a>00222 
<a name="l00223"></a>00223     <a class="code" href="classnih_1_1_bvh__sah__builder.html#aa056c2970c0dcf4f155f90f7a56355eb">build</a>( n_entities, bvh, stats );
<a name="l00224"></a>00224 }
<a name="l00225"></a>00225 <span class="comment">// build</span>
<a name="l00226"></a>00226 <span class="comment">//</span>
<a name="l00227"></a>00227 <span class="comment">// Iterator is supposed to dereference to a Bbox3f</span>
<a name="l00228"></a>00228 <span class="comment">//</span>
<a name="l00229"></a>00229 <span class="comment">// \param begin            first point</span>
<a name="l00230"></a>00230 <span class="comment">// \param end              last point</span>
<a name="l00231"></a>00231 <span class="comment">// \param bvh              output bvh</span>
<a name="l00232"></a>00232 <span class="keyword">template</span> &lt;<span class="keyword">typename</span> Iterator, <span class="keyword">typename</span> CostIterator&gt;
<a name="l00233"></a><a class="code" href="classnih_1_1_bvh__sah__builder.html#a269b237d912be53b8483c63d7c9e06fe">00233</a> <span class="keywordtype">void</span> <a class="code" href="classnih_1_1_bvh__sah__builder.html#aa056c2970c0dcf4f155f90f7a56355eb">Bvh_sah_builder::build</a>(
<a name="l00234"></a>00234     Iterator        begin,
<a name="l00235"></a>00235     Iterator        end,
<a name="l00236"></a>00236     CostIterator    cost_begin,
<a name="l00237"></a>00237     <a class="code" href="structnih_1_1_bvh.html">Bvh_type</a>*       bvh,
<a name="l00238"></a>00238     <a class="code" href="structnih_1_1_bvh__sah__builder_1_1_stats.html">Stats</a>*          stats)
<a name="l00239"></a>00239 {
<a name="l00240"></a>00240     <span class="keyword">const</span> uint32 n_entities = uint32( end - begin );
<a name="l00241"></a>00241 
<a name="l00242"></a>00242     m_entities.resize( n_entities );
<a name="l00243"></a>00243     uint32 i = 0;
<a name="l00244"></a>00244     <span class="keywordflow">for</span> (Iterator it = begin; it != end; ++it)
<a name="l00245"></a>00245     {
<a name="l00246"></a>00246         m_entities[i].m_bbox  = *it;
<a name="l00247"></a>00247         m_entities[i].m_index = i;
<a name="l00248"></a>00248         m_entities[i].m_cost  = cost_begin[i];
<a name="l00249"></a>00249 
<a name="l00250"></a>00250         i++;
<a name="l00251"></a>00251     }
<a name="l00252"></a>00252 
<a name="l00253"></a>00253     <a class="code" href="classnih_1_1_bvh__sah__builder.html#aa056c2970c0dcf4f155f90f7a56355eb">build</a>( n_entities, bvh, stats );
<a name="l00254"></a>00254 }
<a name="l00255"></a>00255 
<a name="l00256"></a>00256 <span class="comment">// Predicate to sort indices based on their entity&#39;s AABB center.</span>
<a name="l00257"></a><a class="code" href="classnih_1_1_bvh__sah__builder_1_1_predicate.html">00257</a> <span class="keyword">class </span><a class="code" href="classnih_1_1_bvh__sah__builder_1_1_predicate.html">Bvh_sah_builder::Predicate</a>
<a name="l00258"></a>00258 {
<a name="l00259"></a>00259 <span class="keyword">public</span>:
<a name="l00260"></a>00260     <a class="code" href="classnih_1_1_bvh__sah__builder_1_1_predicate.html">Predicate</a>(<span class="keywordtype">int</span> dim) : m_dim( dim ) {}
<a name="l00261"></a>00261 
<a name="l00262"></a>00262     <span class="keywordtype">bool</span> operator() (<span class="keyword">const</span> Entity&amp; lhs, <span class="keyword">const</span> Entity&amp; rhs)<span class="keyword"> const</span>
<a name="l00263"></a>00263 <span class="keyword">    </span>{
<a name="l00264"></a>00264         <span class="keyword">const</span> <span class="keywordtype">float</span> leftval  = lhs.m_bbox[0][m_dim] + lhs.m_bbox[1][m_dim];
<a name="l00265"></a>00265         <span class="keyword">const</span> <span class="keywordtype">float</span> rightval = rhs.m_bbox[0][m_dim] + rhs.m_bbox[1][m_dim];
<a name="l00266"></a>00266 
<a name="l00267"></a>00267         <span class="keywordflow">if</span> (leftval == rightval)
<a name="l00268"></a>00268             <span class="keywordflow">return</span> lhs.m_index &lt; rhs.m_index;
<a name="l00269"></a>00269 
<a name="l00270"></a>00270         <span class="keywordflow">return</span> leftval &lt; rightval;
<a name="l00271"></a>00271     }
<a name="l00272"></a>00272 
<a name="l00273"></a>00273 <span class="keyword">private</span>:
<a name="l00274"></a>00274     <span class="keywordtype">int</span> m_dim;
<a name="l00275"></a>00275 };
<a name="l00276"></a>00276 
<a name="l00277"></a>00277 <span class="keyword">inline</span> <span class="keywordtype">float</span> Bvh_sah_builder::area(<span class="keyword">const</span> <a class="code" href="structnih_1_1_bbox.html">Bbox3f</a>&amp; bbox)
<a name="l00278"></a>00278 {
<a name="l00279"></a>00279     <span class="keyword">const</span> <a class="code" href="structnih_1_1_vector.html">Vector3f</a> edge = bbox[1] - bbox[0];
<a name="l00280"></a>00280     <span class="keywordflow">return</span> edge[0] * edge[1] + edge[2] * (edge[0] + edge[1]);
<a name="l00281"></a>00281 }
<a name="l00282"></a>00282 
<a name="l00283"></a>00283 <span class="keyword">inline</span> <span class="keywordtype">bool</span> Bvh_sah_builder::find_largest_axis_split(
<a name="l00284"></a>00284     <span class="keyword">const</span> Node&amp; node,
<a name="l00285"></a>00285     uint32&amp;     pivot,
<a name="l00286"></a>00286     Bbox_type&amp;  left_bb,
<a name="l00287"></a>00287     Bbox_type&amp;  right_bb)
<a name="l00288"></a>00288 {
<a name="l00289"></a>00289     <span class="keyword">const</span> uint32 begin = node.m_begin;
<a name="l00290"></a>00290     <span class="keyword">const</span> uint32 end   = node.m_end;
<a name="l00291"></a>00291     <span class="keyword">const</span> uint32 n_entities = end - begin;
<a name="l00292"></a>00292     <span class="keywordflow">if</span> (m_bboxes.size() &lt; n_entities+1)
<a name="l00293"></a>00293         m_bboxes.resize( n_entities+1 );
<a name="l00294"></a>00294     <span class="keywordflow">if</span> (m_costs.size() &lt; n_entities+1)
<a name="l00295"></a>00295         m_costs.resize( n_entities+1 );
<a name="l00296"></a>00296 
<a name="l00297"></a>00297     <span class="keywordtype">float</span> min_cost = <a class="code" href="group__vectors.html#gab2b34b1991185fc29890973777b60e54">std::numeric_limits&lt;float&gt;::max</a>();
<a name="l00298"></a>00298     <span class="keywordtype">int</span>   min_dim  = -1;
<a name="l00299"></a>00299 
<a name="l00300"></a>00300     <span class="keyword">const</span> Vector_type edge = node.m_bbox[1] - node.m_bbox[0];
<a name="l00301"></a>00301     <span class="keyword">const</span> <span class="keywordtype">int</span> dim = <a class="code" href="group__vectors.html#ga549a2d3c8b77b652dc1cd56c1d119b77">max_element</a>( edge );
<a name="l00302"></a>00302 
<a name="l00303"></a>00303     Predicate predicate( dim );
<a name="l00304"></a>00304 
<a name="l00305"></a>00305     m_bboxes[0] = Bbox_type();
<a name="l00306"></a>00306     m_costs[0]  = 0.0f;
<a name="l00307"></a>00307 
<a name="l00308"></a>00308     std::vector&lt;int&gt;&amp; indices = m_indices[dim];
<a name="l00309"></a>00309 
<a name="l00310"></a>00310     <span class="comment">// Accumulate right hand side bboxes.</span>
<a name="l00311"></a>00311     <span class="keywordflow">for</span>(uint32 i = 1; i &lt;= n_entities; ++i)
<a name="l00312"></a>00312         m_bboxes[i] = Bbox_type( m_bboxes[i-1], m_entities[ indices[ end - i ] ].m_bbox );
<a name="l00313"></a>00313 
<a name="l00314"></a>00314     <span class="keywordflow">for</span>(uint32 i = 1; i &lt;= n_entities; ++i)
<a name="l00315"></a>00315         m_costs[i] = m_costs[i-1] + m_entities[ indices[ end - i ] ].m_cost;
<a name="l00316"></a>00316 
<a name="l00317"></a>00317     <span class="comment">// Loop over possible splits and find the cheapest one.</span>
<a name="l00318"></a>00318     Bbox_type lbb, rbb;
<a name="l00319"></a>00319     <span class="keywordtype">float</span>     lc = 0.0f, rc;
<a name="l00320"></a>00320 
<a name="l00321"></a>00321     <span class="keywordflow">for</span>(uint32 num_left = 1; num_left &lt; n_entities; ++num_left)
<a name="l00322"></a>00322     {
<a name="l00323"></a>00323         <span class="keyword">const</span> <span class="keywordtype">int</span> num_right = n_entities - num_left;
<a name="l00324"></a>00324 
<a name="l00325"></a>00325         rbb = m_bboxes[num_right];
<a name="l00326"></a>00326         lbb.insert( m_entities[ indices[ begin + num_left - 1 ] ].m_bbox );
<a name="l00327"></a>00327 
<a name="l00328"></a>00328         rc  = m_costs[num_right];
<a name="l00329"></a>00329         lc += m_entities[ indices[ begin + num_left - 1 ] ].m_cost;
<a name="l00330"></a>00330 
<a name="l00331"></a>00331         <span class="keywordflow">if</span> (m_force_alignment &amp;&amp; (num_left % m_max_leaf_size != 0))
<a name="l00332"></a>00332             <span class="keywordflow">continue</span>;
<a name="l00333"></a>00333 
<a name="l00334"></a>00334         <span class="keyword">const</span> <span class="keywordtype">float</span> sa_left  = area( lbb );
<a name="l00335"></a>00335         <span class="keyword">const</span> <span class="keywordtype">float</span> sa_right = area( rbb );
<a name="l00336"></a>00336 
<a name="l00337"></a>00337         <span class="keyword">const</span> <span class="keywordtype">float</span> cost = sa_left*lc + sa_right*rc;
<a name="l00338"></a>00338 
<a name="l00339"></a>00339         <span class="keywordflow">if</span>(cost &lt; min_cost)
<a name="l00340"></a>00340         {
<a name="l00341"></a>00341             min_cost = cost;
<a name="l00342"></a>00342             min_dim  = dim;
<a name="l00343"></a>00343             pivot    = begin + num_left;
<a name="l00344"></a>00344             left_bb  = lbb;
<a name="l00345"></a>00345             right_bb = rbb;
<a name="l00346"></a>00346         }
<a name="l00347"></a>00347     }
<a name="l00348"></a>00348 
<a name="l00349"></a>00349     <span class="keywordflow">if</span> (min_dim == -1)
<a name="l00350"></a>00350         <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00351"></a>00351 
<a name="l00352"></a>00352     <span class="comment">// Compute the cost for the current node.</span>
<a name="l00353"></a>00353     <span class="keyword">const</span> <span class="keywordtype">float</span> curr_cost = area( node.m_bbox ) * n_entities;
<a name="l00354"></a>00354 
<a name="l00355"></a>00355     <span class="comment">// Don&#39;t split if the split is more expensive than the current node.</span>
<a name="l00356"></a>00356     <span class="keywordflow">if</span> (m_force_splitting == <span class="keyword">false</span> &amp;&amp; curr_cost * 1.5f &lt; min_cost <span class="comment">/*TODO: remove magic constant*/</span> )
<a name="l00357"></a>00357         <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00358"></a>00358 
<a name="l00359"></a>00359     <span class="comment">// Tag the entities whether they&#39;re left or right according to the winner split.</span>
<a name="l00360"></a>00360     <span class="keyword">const</span> <span class="keywordtype">int</span>* indices_ptr = &amp;m_indices[min_dim][0];
<a name="l00361"></a>00361     <span class="keywordflow">for</span> (uint32 i = begin; i &lt; pivot; ++i)
<a name="l00362"></a>00362         m_tag_bits[indices_ptr[i]] = <span class="keyword">false</span>;
<a name="l00363"></a>00363     <span class="keywordflow">for</span> (uint32 i = pivot; i &lt; end; ++i)
<a name="l00364"></a>00364         m_tag_bits[indices_ptr[i]] = <span class="keyword">true</span>;
<a name="l00365"></a>00365 
<a name="l00366"></a>00366     <span class="comment">// Rearrange the indices of the non-winner dimensions to sorted left/right.</span>
<a name="l00367"></a>00367     <span class="keywordflow">for</span> (<span class="keywordtype">int</span> d = 1; d &lt;= 2; ++d)
<a name="l00368"></a>00368     {
<a name="l00369"></a>00369         <span class="keyword">const</span> <span class="keywordtype">int</span> dim = (min_dim+d) % 3;
<a name="l00370"></a>00370         <span class="keywordtype">int</span> leftpos  = begin;
<a name="l00371"></a>00371         <span class="keywordtype">int</span> rightpos = pivot;
<a name="l00372"></a>00372 
<a name="l00373"></a>00373         <span class="keyword">const</span> <span class="keywordtype">int</span>* indices_ptr = &amp;m_indices[dim][0];
<a name="l00374"></a>00374         <span class="keywordflow">for</span> (uint32 i = begin; i &lt; end; ++i)
<a name="l00375"></a>00375         {
<a name="l00376"></a>00376             <span class="keyword">const</span> <span class="keywordtype">int</span> <a class="code" href="classnih_1_1_bvh__sah__builder.html#a8a807a067d1870d23313781ee76a9e34" title="remapped point index">index</a> = indices_ptr[i];
<a name="l00377"></a>00377 
<a name="l00378"></a>00378             <span class="keywordflow">if</span> (m_tag_bits[index])
<a name="l00379"></a>00379                 m_tmpInt[rightpos++] = <a class="code" href="classnih_1_1_bvh__sah__builder.html#a8a807a067d1870d23313781ee76a9e34" title="remapped point index">index</a>;
<a name="l00380"></a>00380             <span class="keywordflow">else</span>
<a name="l00381"></a>00381                 m_tmpInt[leftpos++] = <a class="code" href="classnih_1_1_bvh__sah__builder.html#a8a807a067d1870d23313781ee76a9e34" title="remapped point index">index</a>;
<a name="l00382"></a>00382         }
<a name="l00383"></a>00383 
<a name="l00384"></a>00384         <span class="comment">// Copy the working array back to indices.</span>
<a name="l00385"></a>00385         memcpy( &amp;m_indices[dim][begin], &amp;m_tmpInt[begin], <span class="keyword">sizeof</span>(<span class="keywordtype">int</span>)*n_entities );
<a name="l00386"></a>00386     }
<a name="l00387"></a>00387     <span class="keywordflow">return</span> <span class="keyword">true</span>;
<a name="l00388"></a>00388 }
<a name="l00389"></a>00389 
<a name="l00390"></a>00390 <span class="keyword">inline</span> <span class="keywordtype">bool</span> Bvh_sah_builder::find_best_split(
<a name="l00391"></a>00391     <span class="keyword">const</span> Node&amp; node,
<a name="l00392"></a>00392     uint32&amp;     pivot,
<a name="l00393"></a>00393     Bbox_type&amp;  left_bb,
<a name="l00394"></a>00394     Bbox_type&amp;  right_bb)
<a name="l00395"></a>00395 {
<a name="l00396"></a>00396     <span class="keyword">const</span> uint32 begin = node.m_begin;
<a name="l00397"></a>00397     <span class="keyword">const</span> uint32 end   = node.m_end;
<a name="l00398"></a>00398     <span class="keyword">const</span> uint32 n_entities = end - begin;
<a name="l00399"></a>00399 
<a name="l00400"></a>00400     <span class="keywordflow">if</span> (n_entities &gt; m_single_axis_threshold)
<a name="l00401"></a>00401         <span class="keywordflow">return</span> find_largest_axis_split( node, pivot, left_bb, right_bb );
<a name="l00402"></a>00402 
<a name="l00403"></a>00403     <span class="keywordflow">if</span> (m_bboxes.size() &lt; n_entities+1)
<a name="l00404"></a>00404         m_bboxes.resize( n_entities+1 );
<a name="l00405"></a>00405     <span class="keywordflow">if</span> (m_costs.size() &lt; n_entities+1)
<a name="l00406"></a>00406         m_costs.resize( n_entities+1 );
<a name="l00407"></a>00407 
<a name="l00408"></a>00408     <span class="keywordtype">float</span> min_cost = <a class="code" href="group__vectors.html#gab2b34b1991185fc29890973777b60e54">std::numeric_limits&lt;float&gt;::max</a>();
<a name="l00409"></a>00409     <span class="keywordtype">int</span>   min_dim  = -1;
<a name="l00410"></a>00410 
<a name="l00411"></a>00411     <span class="comment">// Find the least costly split for each dimension.</span>
<a name="l00412"></a>00412     <span class="keywordflow">for</span>(<span class="keywordtype">int</span> dim = 0; dim &lt; 3; ++dim)
<a name="l00413"></a>00413     {
<a name="l00414"></a>00414         Predicate predicate( dim );
<a name="l00415"></a>00415 
<a name="l00416"></a>00416         m_bboxes[0] = Bbox_type();
<a name="l00417"></a>00417         m_costs[0]  = 0.0f;
<a name="l00418"></a>00418 
<a name="l00419"></a>00419         std::vector&lt;int&gt;&amp; indices = m_indices[dim];
<a name="l00420"></a>00420 
<a name="l00421"></a>00421         <span class="comment">// Accumulate right hand side bboxes.</span>
<a name="l00422"></a>00422         <span class="keywordflow">for</span>(uint32 i = 1; i &lt;= n_entities; ++i)
<a name="l00423"></a>00423             m_bboxes[i] = Bbox_type( m_bboxes[i-1], m_entities[ indices[ end - i ] ].m_bbox );
<a name="l00424"></a>00424 
<a name="l00425"></a>00425         <span class="keywordflow">for</span>(uint32 i = 1; i &lt;= n_entities; ++i)
<a name="l00426"></a>00426             m_costs[i] = m_costs[i-1] + m_entities[ indices[ end - i ] ].m_cost;
<a name="l00427"></a>00427 
<a name="l00428"></a>00428         <span class="comment">// Loop over possible splits and find the cheapest one.</span>
<a name="l00429"></a>00429         Bbox_type lbb, rbb;
<a name="l00430"></a>00430         <span class="keywordtype">float</span>     lc = 0.0f, rc;
<a name="l00431"></a>00431 
<a name="l00432"></a>00432         <span class="keywordflow">for</span>(uint32 num_left = 1; num_left &lt; n_entities; ++num_left)
<a name="l00433"></a>00433         {
<a name="l00434"></a>00434             <span class="keyword">const</span> <span class="keywordtype">int</span> num_right = n_entities - num_left;
<a name="l00435"></a>00435 
<a name="l00436"></a>00436             rbb = m_bboxes[num_right];
<a name="l00437"></a>00437             lbb.insert( m_entities[ indices[ begin + num_left - 1 ] ].m_bbox );
<a name="l00438"></a>00438 
<a name="l00439"></a>00439             rc  = m_costs[num_right];
<a name="l00440"></a>00440             lc += m_entities[ indices[ begin + num_left - 1 ] ].m_cost;
<a name="l00441"></a>00441 
<a name="l00442"></a>00442             <span class="keywordflow">if</span> (m_force_alignment &amp;&amp; (num_left % m_max_leaf_size != 0))
<a name="l00443"></a>00443                 <span class="keywordflow">continue</span>;
<a name="l00444"></a>00444 
<a name="l00445"></a>00445             <span class="keyword">const</span> <span class="keywordtype">float</span> sa_left  = area( lbb );
<a name="l00446"></a>00446             <span class="keyword">const</span> <span class="keywordtype">float</span> sa_right = area( rbb );
<a name="l00447"></a>00447 
<a name="l00448"></a>00448             <span class="keyword">const</span> <span class="keywordtype">float</span> cost = sa_left*lc + sa_right*rc;
<a name="l00449"></a>00449 
<a name="l00450"></a>00450             <span class="keywordflow">if</span>(cost &lt; min_cost)
<a name="l00451"></a>00451             {
<a name="l00452"></a>00452                 min_cost = cost;
<a name="l00453"></a>00453                 min_dim  = dim;
<a name="l00454"></a>00454                 pivot    = begin + num_left;
<a name="l00455"></a>00455                 left_bb  = lbb;
<a name="l00456"></a>00456                 right_bb = rbb;
<a name="l00457"></a>00457             }
<a name="l00458"></a>00458         }
<a name="l00459"></a>00459     }
<a name="l00460"></a>00460 
<a name="l00461"></a>00461     <span class="keywordflow">if</span> (min_dim == -1)
<a name="l00462"></a>00462         <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00463"></a>00463 
<a name="l00464"></a>00464     <span class="comment">// Compute the cost for the current node.</span>
<a name="l00465"></a>00465     <span class="keyword">const</span> <span class="keywordtype">float</span> curr_cost = area( node.m_bbox ) * n_entities;
<a name="l00466"></a>00466 
<a name="l00467"></a>00467     <span class="comment">// Don&#39;t split if the split is more expensive than the current node.</span>
<a name="l00468"></a>00468     <span class="keywordflow">if</span> (m_force_splitting == <span class="keyword">false</span> &amp;&amp; curr_cost * 1.5f &lt; min_cost <span class="comment">/*TODO: remove magic constant*/</span> )
<a name="l00469"></a>00469         <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00470"></a>00470 
<a name="l00471"></a>00471     <span class="comment">// Tag the entities whether they&#39;re left or right according to the winner split.</span>
<a name="l00472"></a>00472     <span class="keyword">const</span> <span class="keywordtype">int</span>* indices_ptr = &amp;m_indices[min_dim][0];
<a name="l00473"></a>00473     <span class="keywordflow">for</span> (uint32 i = begin; i &lt; pivot; ++i)
<a name="l00474"></a>00474         m_tag_bits[indices_ptr[i]] = <span class="keyword">false</span>;
<a name="l00475"></a>00475     <span class="keywordflow">for</span> (uint32 i = pivot; i &lt; end; ++i)
<a name="l00476"></a>00476         m_tag_bits[indices_ptr[i]] = <span class="keyword">true</span>;
<a name="l00477"></a>00477 
<a name="l00478"></a>00478     <span class="comment">// Rearrange the indices of the non-winner dimensions to sorted left/right.</span>
<a name="l00479"></a>00479     <span class="keywordflow">for</span> (<span class="keywordtype">int</span> d = 1; d &lt;= 2; ++d)
<a name="l00480"></a>00480     {
<a name="l00481"></a>00481         <span class="keyword">const</span> <span class="keywordtype">int</span> dim = (min_dim+d) % 3;
<a name="l00482"></a>00482         <span class="keywordtype">int</span> leftpos  = begin;
<a name="l00483"></a>00483         <span class="keywordtype">int</span> rightpos = pivot;
<a name="l00484"></a>00484 
<a name="l00485"></a>00485         <span class="keyword">const</span> <span class="keywordtype">int</span>* indices_ptr = &amp;m_indices[dim][0];
<a name="l00486"></a>00486         <span class="keywordflow">for</span> (uint32 i = begin; i &lt; end; ++i)
<a name="l00487"></a>00487         {
<a name="l00488"></a>00488             <span class="keyword">const</span> <span class="keywordtype">int</span> <a class="code" href="classnih_1_1_bvh__sah__builder.html#a8a807a067d1870d23313781ee76a9e34" title="remapped point index">index</a> = indices_ptr[i];
<a name="l00489"></a>00489 
<a name="l00490"></a>00490             <span class="keywordflow">if</span> (m_tag_bits[index])
<a name="l00491"></a>00491                 m_tmpInt[rightpos++] = <a class="code" href="classnih_1_1_bvh__sah__builder.html#a8a807a067d1870d23313781ee76a9e34" title="remapped point index">index</a>;
<a name="l00492"></a>00492             <span class="keywordflow">else</span>
<a name="l00493"></a>00493                 m_tmpInt[leftpos++] = <a class="code" href="classnih_1_1_bvh__sah__builder.html#a8a807a067d1870d23313781ee76a9e34" title="remapped point index">index</a>;
<a name="l00494"></a>00494         }
<a name="l00495"></a>00495 
<a name="l00496"></a>00496         <span class="comment">// Copy the working array back to indices.</span>
<a name="l00497"></a>00497         memcpy( &amp;m_indices[dim][begin], &amp;m_tmpInt[begin], <span class="keyword">sizeof</span>(<span class="keywordtype">int</span>)*n_entities );
<a name="l00498"></a>00498     }
<a name="l00499"></a>00499     <span class="keywordflow">return</span> <span class="keyword">true</span>;
<a name="l00500"></a>00500 }
<a name="l00501"></a>00501 
<a name="l00502"></a>00502 <span class="keyword">inline</span> <span class="keywordtype">void</span> Bvh_sah_builder::compute_bbox(
<a name="l00503"></a>00503     <span class="keyword">const</span> uint32      begin,
<a name="l00504"></a>00504     <span class="keyword">const</span> uint32      end,
<a name="l00505"></a>00505     Bbox_type&amp;          bbox)
<a name="l00506"></a>00506 {
<a name="l00507"></a>00507     bbox = Bbox_type();
<a name="l00508"></a>00508     <span class="keywordflow">for</span> (uint32 i = begin; i &lt; end; i++)
<a name="l00509"></a>00509         bbox.insert( m_entities[m_indices[0][i]].m_bbox );
<a name="l00510"></a>00510 }
<a name="l00511"></a>00511 
<a name="l00512"></a>00512 <span class="keyword">namespace </span>deprecated {
<a name="l00513"></a>00513 
<a name="l00514"></a>00514 <span class="keyword">template</span> &lt;<span class="keyword">typename</span> Iterator&gt;
<a name="l00515"></a><a class="code" href="classnih_1_1deprecated_1_1_bvh__sah__builder.html#a7fb4a776c2409db6e3db887fc49b7023">00515</a> <span class="keywordtype">void</span> <a class="code" href="classnih_1_1deprecated_1_1_bvh__sah__builder.html#a7fb4a776c2409db6e3db887fc49b7023">Bvh_sah_builder::build</a>(
<a name="l00516"></a>00516         <span class="keyword">const</span> Iterator  begin,
<a name="l00517"></a>00517         <span class="keyword">const</span> Iterator  end,
<a name="l00518"></a>00518         <a class="code" href="structnih_1_1_bvh.html">Bvh_type</a>*               bvh)
<a name="l00519"></a>00519 {
<a name="l00520"></a>00520         m_entities.resize( end - begin );
<a name="l00521"></a>00521         uint32 i = 0;
<a name="l00522"></a>00522         <span class="keywordflow">for</span> (Iterator it = begin; it != end; ++it)
<a name="l00523"></a>00523         {
<a name="l00524"></a>00524                 m_entities[i].m_bbox  = *it;
<a name="l00525"></a>00525                 m_entities[i].m_index = i;
<a name="l00526"></a>00526 
<a name="l00527"></a>00527                 i++;
<a name="l00528"></a>00528         }
<a name="l00529"></a>00529 
<a name="l00530"></a>00530         <span class="comment">// create root</span>
<a name="l00531"></a>00531         Node_stack node_stack;
<a name="l00532"></a>00532         {
<a name="l00533"></a>00533                 Node node;
<a name="l00534"></a>00534                 compute_bbox( 0u, uint32(end - begin), node.m_bbox );
<a name="l00535"></a>00535                 node.m_begin = 0u;
<a name="l00536"></a>00536                 node.m_end   = uint32(end - begin);
<a name="l00537"></a>00537                 node.m_depth = 0u;
<a name="l00538"></a>00538                 node.m_node  = 0u;
<a name="l00539"></a>00539 
<a name="l00540"></a>00540                 node_stack.push( node );
<a name="l00541"></a>00541         }
<a name="l00542"></a>00542 
<a name="l00543"></a>00543         <a class="code" href="structnih_1_1_bvh__node.html">Bvh_node</a> root;
<a name="l00544"></a>00544         root.<a class="code" href="structnih_1_1_bvh__node.html#ab09c9d3422fee1af8c59f71af6ecf64a">set_type</a>( Bvh_node::kLeaf );
<a name="l00545"></a>00545         root.<a class="code" href="structnih_1_1_bvh__node.html#a06c1cb6707abd1528279589bece1219b">set_index</a>( 0u );
<a name="l00546"></a>00546         bvh-&gt;m_nodes.push_back( root );
<a name="l00547"></a>00547         bvh-&gt;m_bboxes.resize( 1u );
<a name="l00548"></a>00548 
<a name="l00549"></a>00549         <span class="keywordflow">while</span> (node_stack.empty() == <span class="keyword">false</span>)
<a name="l00550"></a>00550         {
<a name="l00551"></a>00551                 <span class="keyword">const</span> Node node = node_stack.top();
<a name="l00552"></a>00552                 node_stack.pop();
<a name="l00553"></a>00553                 
<a name="l00554"></a>00554                 <span class="keyword">const</span> uint32 node_index = node.m_node;
<a name="l00555"></a>00555                 <span class="keyword">const</span> <a class="code" href="structnih_1_1_bbox.html">Bbox_type</a> bbox    = node.m_bbox;
<a name="l00556"></a>00556 
<a name="l00557"></a>00557                 bvh-&gt;m_bboxes[ node_index ] = bbox;
<a name="l00558"></a>00558 
<a name="l00559"></a>00559                 <span class="keywordflow">if</span> (node.m_end - node.m_begin &lt; m_max_leaf_size)
<a name="l00560"></a>00560                 {
<a name="l00561"></a>00561                         <span class="comment">//</span>
<a name="l00562"></a>00562                         <span class="comment">// Make a leaf node</span>
<a name="l00563"></a>00563                         <span class="comment">//</span>
<a name="l00564"></a>00564                         <a class="code" href="structnih_1_1_bvh__node.html">Bvh_node</a>&amp; bvh_node = bvh-&gt;m_nodes[ node_index ];
<a name="l00565"></a>00565 
<a name="l00566"></a>00566                         bvh_node.<a class="code" href="structnih_1_1_bvh__node.html#ab09c9d3422fee1af8c59f71af6ecf64a">set_type</a>( Bvh_node::kLeaf );
<a name="l00567"></a>00567                         bvh_node.<a class="code" href="structnih_1_1_bvh__node.html#a06c1cb6707abd1528279589bece1219b">set_index</a>( uint32( bvh-&gt;m_leaves.size() ) );
<a name="l00568"></a>00568                         bvh-&gt;m_leaves.push_back( <a class="code" href="structnih_1_1_bvh__leaf.html">Bvh_leaf</a>( node.m_end - node.m_begin, node.m_begin ) );
<a name="l00569"></a>00569                 }
<a name="l00570"></a>00570                 <span class="keywordflow">else</span>
<a name="l00571"></a>00571                 {
<a name="l00572"></a>00572                         <span class="comment">//</span>
<a name="l00573"></a>00573                         <span class="comment">// Make a split node</span>
<a name="l00574"></a>00574                         <span class="comment">//</span>
<a name="l00575"></a>00575 
<a name="l00576"></a>00576                         uint32          middle;
<a name="l00577"></a>00577                         <a class="code" href="structnih_1_1_bbox.html">Bbox_type</a>       l_bb, r_bb;
<a name="l00578"></a>00578 
<a name="l00579"></a>00579                         <span class="keywordflow">if</span> (find_best_split( node, middle, l_bb, r_bb ) == <span class="keyword">false</span>)
<a name="l00580"></a>00580                         {
<a name="l00581"></a>00581                                 <span class="comment">// unsuccessful split: make a leaf node</span>
<a name="l00582"></a>00582                                 <a class="code" href="structnih_1_1_bvh__node.html">Bvh_node</a>&amp; bvh_node = bvh-&gt;m_nodes[ node_index ];
<a name="l00583"></a>00583 
<a name="l00584"></a>00584                                 bvh_node.<a class="code" href="structnih_1_1_bvh__node.html#ab09c9d3422fee1af8c59f71af6ecf64a">set_type</a>( Bvh_node::kLeaf );
<a name="l00585"></a>00585                                 bvh_node.<a class="code" href="structnih_1_1_bvh__node.html#a06c1cb6707abd1528279589bece1219b">set_index</a>( uint32( bvh-&gt;m_leaves.size() ) );
<a name="l00586"></a>00586                                 bvh-&gt;m_leaves.push_back( <a class="code" href="structnih_1_1_bvh__leaf.html">Bvh_leaf</a>( node.m_end - node.m_begin, node.m_begin ) );
<a name="l00587"></a>00587                                 <span class="keywordflow">continue</span>;
<a name="l00588"></a>00588                         }
<a name="l00589"></a>00589 
<a name="l00590"></a>00590                         <span class="comment">// alloc space for children</span>
<a name="l00591"></a>00591                         <span class="keyword">const</span> uint32 left_node_index = uint32( bvh-&gt;m_nodes.size() );
<a name="l00592"></a>00592                         bvh-&gt;m_nodes.resize( left_node_index + 2 );
<a name="l00593"></a>00593                         bvh-&gt;m_bboxes.resize( left_node_index + 2 );
<a name="l00594"></a>00594 
<a name="l00595"></a>00595                         <a class="code" href="structnih_1_1_bvh__node.html">Bvh_node</a>&amp; bvh_node = bvh-&gt;m_nodes[ node_index ];
<a name="l00596"></a>00596                         bvh_node.<a class="code" href="structnih_1_1_bvh__node.html#ab09c9d3422fee1af8c59f71af6ecf64a">set_type</a>( Bvh_node::kInternal );
<a name="l00597"></a>00597                         bvh_node.<a class="code" href="structnih_1_1_bvh__node.html#a06c1cb6707abd1528279589bece1219b">set_index</a>( left_node_index );
<a name="l00598"></a>00598 
<a name="l00599"></a>00599                         <span class="comment">// push left and right children in processing queue</span>
<a name="l00600"></a>00600                         Node right_node;
<a name="l00601"></a>00601                         right_node.m_bbox  = r_bb;
<a name="l00602"></a>00602                         right_node.m_begin = middle;
<a name="l00603"></a>00603                         right_node.m_end   = node.m_end;
<a name="l00604"></a>00604                         right_node.m_depth = node.m_depth + 1u;
<a name="l00605"></a>00605                         right_node.m_node  = left_node_index + 1u;
<a name="l00606"></a>00606                         node_stack.push( right_node );
<a name="l00607"></a>00607 
<a name="l00608"></a>00608                         Node left_node;
<a name="l00609"></a>00609                         left_node.m_bbox  = l_bb;
<a name="l00610"></a>00610                         left_node.m_begin = node.m_begin;
<a name="l00611"></a>00611                         left_node.m_end   = middle;
<a name="l00612"></a>00612                         left_node.m_depth = node.m_depth + 1u;
<a name="l00613"></a>00613                         left_node.m_node  = left_node_index;
<a name="l00614"></a>00614                         node_stack.push( left_node );
<a name="l00615"></a>00615                 }
<a name="l00616"></a>00616         }
<a name="l00617"></a>00617 
<a name="l00618"></a>00618         build_skip_nodes( &amp;bvh-&gt;m_nodes[0], &amp;bvh-&gt;m_nodes[0], uint32(-1) );
<a name="l00619"></a>00619 }
<a name="l00620"></a>00620 
<a name="l00621"></a>00621 
<a name="l00622"></a>00622 <span class="comment">// Predicate to sort indices based on their entity&#39;s AABB center.</span>
<a name="l00623"></a><a class="code" href="classnih_1_1deprecated_1_1_bvh__sah__builder_1_1_predicate.html">00623</a> <span class="keyword">class </span><a class="code" href="classnih_1_1deprecated_1_1_bvh__sah__builder_1_1_predicate.html">Bvh_sah_builder::Predicate</a>
<a name="l00624"></a>00624 {
<a name="l00625"></a>00625 <span class="keyword">public</span>:
<a name="l00626"></a>00626         <a class="code" href="classnih_1_1deprecated_1_1_bvh__sah__builder_1_1_predicate.html">Predicate</a>(<span class="keywordtype">int</span> dim) : m_dim( dim ) {}
<a name="l00627"></a>00627 
<a name="l00628"></a>00628         <span class="keywordtype">bool</span> operator() (<span class="keyword">const</span> Entity&amp; lhs, <span class="keyword">const</span> Entity&amp; rhs)<span class="keyword"> const</span>
<a name="l00629"></a>00629 <span class="keyword">        </span>{
<a name="l00630"></a>00630                 <span class="keyword">const</span> <span class="keywordtype">float</span> leftval  = lhs.m_bbox[0][m_dim] + lhs.m_bbox[1][m_dim];
<a name="l00631"></a>00631                 <span class="keyword">const</span> <span class="keywordtype">float</span> rightval = rhs.m_bbox[0][m_dim] + rhs.m_bbox[1][m_dim];
<a name="l00632"></a>00632 
<a name="l00633"></a>00633                 <span class="keywordflow">return</span> leftval &lt; rightval;
<a name="l00634"></a>00634         }
<a name="l00635"></a>00635 
<a name="l00636"></a>00636 <span class="keyword">private</span>:
<a name="l00637"></a>00637         <span class="keywordtype">int</span> m_dim;
<a name="l00638"></a>00638 };
<a name="l00639"></a>00639 
<a name="l00640"></a>00640 <span class="keyword">inline</span> <span class="keywordtype">float</span> Bvh_sah_builder::area(<span class="keyword">const</span> <a class="code" href="structnih_1_1_bbox.html">Bbox3f</a>&amp; bbox)
<a name="l00641"></a>00641 {
<a name="l00642"></a>00642         <span class="keyword">const</span> <a class="code" href="structnih_1_1_vector.html">Vector3f</a> edge = bbox[1] - bbox[0];
<a name="l00643"></a>00643         <span class="keywordflow">return</span> edge[0] * edge[1] + edge[2] * (edge[0] + edge[1]);
<a name="l00644"></a>00644 }
<a name="l00645"></a>00645 
<a name="l00646"></a>00646 <span class="keyword">inline</span> <span class="keywordtype">bool</span> Bvh_sah_builder::find_best_split(
<a name="l00647"></a>00647         <span class="keyword">const</span> Node&amp;     node,
<a name="l00648"></a>00648         uint32&amp;         pivot,
<a name="l00649"></a>00649         Bbox_type&amp;      left_bb,
<a name="l00650"></a>00650         Bbox_type&amp;      right_bb)
<a name="l00651"></a>00651 {
<a name="l00652"></a>00652         <span class="keywordtype">float</span>           min_cost = <a class="code" href="group__vectors.html#gab2b34b1991185fc29890973777b60e54">std::numeric_limits&lt;float&gt;::max</a>();
<a name="l00653"></a>00653         <span class="keywordtype">int</span>                     min_dim  = -1;
<a name="l00654"></a>00654 
<a name="l00655"></a>00655         <span class="keyword">const</span> uint32 begin = node.m_begin;
<a name="l00656"></a>00656         <span class="keyword">const</span> uint32 end   = node.m_end;
<a name="l00657"></a>00657         <span class="keyword">const</span> uint32 n_entities = end - begin;
<a name="l00658"></a>00658         <span class="keywordflow">if</span> (m_bboxes.size() &lt; n_entities+1)
<a name="l00659"></a>00659                 m_bboxes.resize( n_entities+1 );
<a name="l00660"></a>00660 
<a name="l00661"></a>00661         <span class="comment">// Find the least costly split for each dimension.</span>
<a name="l00662"></a>00662         <span class="keywordflow">for</span>(<span class="keywordtype">int</span> dim = 0; dim &lt; 3; ++dim)
<a name="l00663"></a>00663         {
<a name="l00664"></a>00664                 Predicate predicate( dim );
<a name="l00665"></a>00665 
<a name="l00666"></a>00666                 <span class="comment">// Sort along current dimension.</span>
<a name="l00667"></a>00667                 std::sort(
<a name="l00668"></a>00668                         &amp;m_entities[0] + begin,
<a name="l00669"></a>00669                         &amp;m_entities[0] + end,
<a name="l00670"></a>00670                         predicate );
<a name="l00671"></a>00671 
<a name="l00672"></a>00672                 m_bboxes[0].clear();
<a name="l00673"></a>00673 
<a name="l00674"></a>00674                 <span class="comment">// Accumulate right hand side bboxes.</span>
<a name="l00675"></a>00675                 <span class="keywordflow">for</span>(uint32 i = 1; i &lt;= n_entities; ++i)
<a name="l00676"></a>00676                 {
<a name="l00677"></a>00677                         m_bboxes[i] = m_bboxes[i-1];
<a name="l00678"></a>00678                         m_bboxes[i].insert( m_entities[ end - i ].m_bbox );
<a name="l00679"></a>00679                 }
<a name="l00680"></a>00680 
<a name="l00681"></a>00681                 <span class="comment">// Loop over possible splits and find the cheapest one.</span>
<a name="l00682"></a>00682                 Bbox_type lbb, rbb;
<a name="l00683"></a>00683 
<a name="l00684"></a>00684                 <span class="keywordflow">for</span>(uint32 num_left = 1; num_left &lt; n_entities; ++num_left)
<a name="l00685"></a>00685                 {
<a name="l00686"></a>00686                         <span class="keyword">const</span> <span class="keywordtype">int</span> num_right = n_entities - num_left;
<a name="l00687"></a>00687 
<a name="l00688"></a>00688                         rbb = m_bboxes[num_right];
<a name="l00689"></a>00689                         lbb.insert( m_entities[ begin + num_left - 1 ].m_bbox );
<a name="l00690"></a>00690 
<a name="l00691"></a>00691                         <span class="keyword">const</span> <span class="keywordtype">float</span> sa_left  = area( lbb );
<a name="l00692"></a>00692                         <span class="keyword">const</span> <span class="keywordtype">float</span> sa_right = area( rbb );
<a name="l00693"></a>00693 
<a name="l00694"></a>00694                         <span class="keyword">const</span> <span class="keywordtype">float</span> cost = sa_left*num_left + sa_right*num_right;
<a name="l00695"></a>00695 
<a name="l00696"></a>00696                         <span class="keywordflow">if</span>(cost &lt; min_cost)
<a name="l00697"></a>00697                         {
<a name="l00698"></a>00698                                 min_cost = cost;
<a name="l00699"></a>00699                                 min_dim  = dim;
<a name="l00700"></a>00700                                 pivot    = begin + num_left;
<a name="l00701"></a>00701                                 left_bb  = lbb;
<a name="l00702"></a>00702                                 right_bb = rbb;
<a name="l00703"></a>00703                         }
<a name="l00704"></a>00704                 }
<a name="l00705"></a>00705         }
<a name="l00706"></a>00706 
<a name="l00707"></a>00707         <span class="comment">// Compute the cost for the current node.</span>
<a name="l00708"></a>00708         <span class="keyword">const</span> <span class="keywordtype">float</span> curr_cost = area( node.m_bbox ) * n_entities;
<a name="l00709"></a>00709 
<a name="l00710"></a>00710         <span class="comment">// Don&#39;t split if the split is more expensive than the current node.</span>
<a name="l00711"></a>00711         <span class="keywordflow">if</span>( curr_cost * 1.5f &lt; min_cost)
<a name="l00712"></a>00712                 <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00713"></a>00713 
<a name="l00714"></a>00714         <span class="comment">// Resort if necessary.</span>
<a name="l00715"></a>00715         <span class="keywordflow">if</span>(min_dim != 2)
<a name="l00716"></a>00716         {
<a name="l00717"></a>00717                 Predicate predicate( min_dim );
<a name="l00718"></a>00718                 std::sort(
<a name="l00719"></a>00719                         &amp;m_entities[0] + begin,
<a name="l00720"></a>00720                         &amp;m_entities[0] + end,
<a name="l00721"></a>00721                         predicate );
<a name="l00722"></a>00722         }
<a name="l00723"></a>00723         <span class="keywordflow">return</span> <span class="keyword">true</span>;
<a name="l00724"></a>00724 }
<a name="l00725"></a>00725 
<a name="l00726"></a>00726 <span class="keyword">inline</span> <span class="keywordtype">void</span> Bvh_sah_builder::compute_bbox(
<a name="l00727"></a>00727         <span class="keyword">const</span> uint32            begin,
<a name="l00728"></a>00728         <span class="keyword">const</span> uint32            end,
<a name="l00729"></a>00729         Bbox_type&amp;                      bbox)
<a name="l00730"></a>00730 {
<a name="l00731"></a>00731         bbox.clear();
<a name="l00732"></a>00732         <span class="keywordflow">for</span> (uint32 i = begin; i &lt; end; i++)
<a name="l00733"></a>00733                 bbox.insert( m_entities[i].m_bbox );
<a name="l00734"></a>00734 }
<a name="l00735"></a>00735 
<a name="l00736"></a>00736 } <span class="comment">// namespace deprecated</span>
<a name="l00737"></a>00737 
<a name="l00738"></a>00738 } <span class="comment">// namespace nih</span>
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